Repressor and int synthesis of bacteriophage lambda in the E. coli host mutant ER437

Analysis of lambda phage infection of the host mutant ER437 by SDS polyacrylamide gel electrophoresis and autoradiography has revealed altered expression of repressor and integration function (Int). We show that in this host Int as well as repressor synthesis is not dependent upon the lambdacIII gene product in the usual manner, nor is their synthesis turned off in the normal way.